Centrifugal pump.



0; v. KERR. GENTRIFUGAL PUMP. APPLICATION FILED AUG"; 27, I913. 1, 125,11 7.. Patented Jan. 19, 1915,

2 SHEETSSHEET 1.

l 1-1 N N l/witnesses 31400441306 (1 Hozmu I l\ 1% i G. V. KERR.

GENTRIFUGAL PUMP.

APPLICATION FILED AUG. 27, 1913.

Patented Jan. 19,1915.

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CHARLES VOLNEY KERR, OF WELLSVILLE, 1\l'IE.SlV-Y.ORKr

CENTRIFUGAL' PUMP.

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Specification of Letters Patent.

Application filed August 27, 1913. Serial no. recess.

To all whom it may concern:

Be itknown that I, CHARLES V. KERR, a citizen of the United States,residing at Wellsville, in the county of Allegany and State of New York,have invented certain new and useful Improvements in Centrifugal Pumps,of which the following is a s pecifieation.

My invention relates to centrifugal pumps in general, and has for itssalient objects to improve the construction ofsuch pumps both as to modeof operation and also as to structural details for the accomplishment ofthe purposes hereinafter set forth.

My object in developing the present type of centrifugal pump is tosecure such .a form, that will have good eificiency when running atsteam turbine speeds, and delivering a large volume of water at lowheads, such as used for condensers in power plants, irrigation systems,and circulating water generally. 7

It has been found that a satisfactory and efficient high speed pump forlarge volumes and low heads and for purposes above mentioned has notbeen available.

The advantage in high speed for turbinedriven pumps is clearly evident,when a certain steam turbine using steam at one hundred pounds gagepressure, with atmospheric exhaust, develops at twelve hundredrevolutions per minute, seventeen brake horse power; at twenty-fourhundred revolutions per minute, the same turbine develops thirty brakehorse power; and at thirty-six hundred revolutions per minute, forty-onebrake horse power. These different horse powers'it has been found aredeveloped by the turbine at the different speeds with precisely the sametotal amount of consumption of steam. As an increased em ciency is alsodeveloped in a pump of my construction at high speeds as compared withordinary slow speed pumps, :1 plant comprising such a high speed turbinecombined with my form of high speed pump further and greatly increasesthe economy or efficiency of the pumping unit. I

A further object of my invention is to construct and arrange the bladeson the impeller which lifts and propels the fluid, so that the same inview of its high velocity, will not not too abruptly in changing thedirection of the movement of the fiuid and cause a churning action andincrease the friction, thereby reducing the efficiency, but

allow a smooth action thereby enabling the full energy of the impellertobe'expended' in proper relationand action on thefluid..

Said. impeller is also soiarranged and constructed with. respeot'i tothe. annular: nozzle.

for the passage of the fiuid' to the outlet,-

Patented Jaa...ra, rear-5 that itwilLautomatically act-under. allconditions ofserviceto uniformly. balance the pressures on both sides orfluidJrecei-vin'g faces of the impeller, and atthe same time centralizesaid impellerwith respectto the annular onnozzle outlet for. the. fluidtothe.

discharge opening. Y

It is for the purpose of. securing to the forth, that I have devised thepresent im-.

provements, a preferred. form of which isshown 111 the: accompanying twosheets forinmg. part of this specification, .inwhich' similar referencecharacters indicate the.

same parts throughout the several figures.

of drawing.

The invention consistsof structural characteristics and relativearrangements: of

elements, whichv will be hereinafter more fully and clearly described,.and'particularly pointedout in the appended claims.-

In the drawings :-Figure 1 is a; transverse section of'thepump on'theline I-I Referring to the drawings .1 is. asuitable casingprovided.witha. water inlet 2-, which is preferably branched or divided into twosymmetrical volute 'suctionchambers 3, 3, for reasonstobe hereinafterexplained. The interior'or central seotioncf'the casing has formedtherein the wellrounded or annular nozzle 4 which leads into thepassageway or discharge conduit 5, also preferably, of voluteshape, saidconduit 5 communicating with-the outlet opening. 6, and being ofgradually. increasing cross sectional area, as shown in Figs. 1 and 2.7, 7 are bearing heads suitably secured or bolted. over the "2o fullest.extentpossible, the accomplishment of the various-objects and.desiderata above Set lateral openings 8, 8, of the casing 11, and eachhead 7 is cast in one piece and arranged as shown in Fig: l with twochambers 9 and 10. The outer chamber 10 contains a dust proof bearing 11provided with the usual opening 12 and lubricating ring 13, while theinner chamber 9 projects into the suc-- tion chamber 3 of the casing 1,and is provided with a striding box 1 1 having any suitable form orpacking 15, the specific form of said bearings 11, and packing 15,forming no essential features of the present invention, as any otherforms may be readily substituted without departing from the spirit oi myinvention,

An impeller shaft 16 passes through the casing 1 and chambers 9 and 10in the heads 7, and is rotatably supported in the bearings 11, as shown.Said shaft may be connected to any form of high speed steam turbine, orelectric motor by means of a flexible coupling, as shown, for example,in my copending application Serial No. 586,629. Attached by a suitablekey or other means, well known in this class of inventions, to saidshaft 16, is a spiroidal runneror impeller 17 preferably made in twosections 17 and 17', as shown in Figs. 3 and 5, and while I have shownthe same as cored,thesame may be solid or in one piece, if so desired.Said sections 17* and 1'? are secured in place by means of sleeves 18firmly secured to the shaft 16, on each side of the impeller or runner1?, and arexso arranged that they rigidly hold'the two sections of theimpeller or runner 17 together in a fixed relation and keep them fromslipping longitudinally on the shaft 16. Said spiroidal impeller orrunner 1'? is of the semi open type and may be made of semi-steel,crucible steel, or non.- corroding alloy or bronze, and when the twosections 1'? and 17* are properly placed together or assembled, aperiphery of V- shape or conoidal section 19 is formed, as shown inFigs. 3 and '5, having an angle 9 with the axis of the impeller. Thevanes-or blades 20, 20 on the colloidal periphery 19 of the impeller 17are so formed and arranged as to form spiroidal working surfaces asshown, said surfaces being generated (see Figs. 3 and 5) by moving aline represented by a-Z making an acute angle 0 with the axis of theimpeller, while moving along a helical directrix represented by the line0Ze, which directrix is inclined at an angle f to a plane normal to theaxis of the impeller. The outer edges of the blades or vanes 20, 20 aresupported and held together by a shroud ring 21 which is preferablycast, as shown,

integral with the impeller.

22, 22, are the inlet edges of the blades or vanes 29, 20, which arespiral instead of radial, and 23, 23, indicate the discharge edges.

In 5 6 is shown an impeller or angle it with the normal outside face orplane of the impeller,

In the forms of impeller 17 illustrated for example in Figs. 3 and 5,six blades or vanes 20 are used on each side, which number may be variedto suit conditions and capacity, if so desired, and will be fully withinthe scope of my invention. it have found that this form of impeller orrunner is not only theoretically correct, but it also permits the vanesand spiroidal working faces to be readily machined or smoothed foraction, thereby reducing the frictional resistances Furthermore, bymaking the impeller 17 in two sections, 17* and 17 the same can becheaply manufactured, easily handled and adjusted, and made perfectlyrigid and balanced, so that it retains its form under illi e unusualhigh speeds.

While my preferred form of impeller is shown in Figs. 3 and 5, in whichthe blaces or vanes 20 on each side of the impeller are directlyopposite each other, 1 haye found that this particular arrangement isnot essary for the successful operation of the pump, and said blades maybe sta gered by simplypartly turning on the shart 16, one of thesections 1? or 17* of the impeller, through any angle, but preferablyone corresponding to one-half the peripheral distance between theapexes'of the blades 20. During the operation of the impeller-i7,

rotating rapidly in the direction of the arrowshown in Figs. 1 and 2,the water iiows through the intake or inlet 2 and is divided and carriedinto the two volute suction chambers 3, 3, and is there properly takenup by'the spiral shaped inlet edges 22, 22, on opposite sides of theimpeller which enter into the streams oi? water like a wedge splittingwood, and the spiroidal shaped working faces of the iinpeller then actfiatwise upon the water, instead of edgewise as in the usual form ofhelical pumps, and the water I? is discharged from the impeller througha Well rounded orifice or annular nozzle l and enters the whitedischarge conduit-5 and is forced through the outlet 6'.

While I have shown a. double suction pump, it will be readily seen thatany form of impeller and casing having suction and discharge chambers,could be adopted for single suction pumps. The double suction has notonly the advantage of double lie ranged with respect ity at the samespeed, but is also self balancing for the reason that if the impeller 17moves to the right of its position shown in Fig. 1, the area of thedischarge from the impeller 17 into the annular nozzle 4 at the rightwill be made smaller or narrower, while that ,on the left will be largeror wider, the result being to increase the discharge head or pressure onthe right and increase the suction on the left, the combined effect ofwhich is to promptly adjust the impeller 17 back toits proper andcentral position where the balancing forces are equalized, saidbalancing force being greatest at maximum discharge and becoming zero atno discharge, or shut-off. j

The lateral openings 8 receiving the bearing heads-7 are slightly largerin diameter than the impeller 17, and by removing one of said bearingheads, the impeller with its shaft 16' can be easily withdrawn from thecasing 1, which construction and arrangement enables the use of a solidcasing, thereby avoiding the use of packed joints required by the usualsplit case construction.

It will be readily seen that owing to the volute shape of the suctionchamber or chambers 3, the relation of the annular; nozzle 4, volutedischarge passage-way 5, v and the spiroidal impeller 17, with respectto said suction chambers 3, the fluid is directed into and moves withthe impeller in a perfect spiral path, thereby taking up movement of theimpeller without any churning action and producing a smooth andefficient operation of the pump.

From the foregoing disclosure it will be readily seen that the casing,bearings, shaft and impeller and its parts, are easily accessible, andthe construction of the pump is such that all the parts of the same maybe cheaply and accurately manufactured and quickly installed andadjusted, or repaired, so as to insure steady and continuous runningunder highest of speeds and with excellent efliciency.

lVhat I claim is v 1. A rotary impeller for centrifugal pumps comprisinga shaft, a conoidal surface surrounding and symmetrically arto the axisof said shaft, and having a base which forms a comb or ridge near theperiphery of said impeller, a series of vanes or or left hand spiroidalsurfaces on said conoidal surface, said spiroidal surfaces beinggenerated by a line which moves at an acute angle with respect to theaxis of the shaft or impeller while moving along a helical .pumpscomprising a faces surrounding and symmetrically arthe rapid bladesarranged as rightdirectrix, and said conoidal surface being generated byrevolving a line about the axis of the shaft.

2. A rotary impeller for centrifugal shaft, conoidal surranged withrespect to the axis of said shaft and having adjoining bases which forma comb or ridge near the middle of said impeller, a seris of vanes or.blades arranged as right and left hand spiroidal surfaces on saidconoidal surfaces, said spiroidal surfaces being generated by a linewhich moves at an acute angle with respect to the axis of the shaft or-impeller while moving along a helical directrix, and said conoidalsurfaces being generated by revolving a line about the axisof the shaft.

3. In a centrifugal pumpthe-combination of a volute casing having inletand'outlet openings with an annular nozzle the interior surfaces ofwhich join smoothly to 'each other, said annular nozzle being generatedby revolving about the axis of said casing the longitudinal mid-sectionof a diverging nozzle having a rounded entrance, said midsection lyingin a plane passing through said axis, and a double suction spiroidalimpeller rotatably, supported centrally with respect to said annularnozzle, having axial movement for the purpose of centering said impellerin proper relation to the nozzle by the action of the fluid discharged.

In a centrifugal pump the combination of a casing having volute suctionand volute discharge conduits, an annular nozzle merging in thetionspiroidal impeller having a central comb or ridge rotatablysupported centrally with respect to said annular nozzle and having axialmovement with respect to said annular nozzle, said parts so constructedand assembled as to produce a self-centering action of the impellerduring discharge of 5. In a centrifugal pump the combination of a casinghaving volute suction and volute discharge conduits, an annular nozzlemerging in the discharge conduit, and a double suction spiroidalimpeller having a central comb or ridge and spiral entering edgesrotatably supported centrally with redischarge conduit, a double-suc

